The island at the end of the world: Bouvetøya

If you want to get away from it all, this is the place for you. If you prefer to experience your volcanoes in utter isolation, you could not do any better. If you have seen it all, come and see this. Find yourself a globe (for younger readers, this is a historical version of google earth without a zoom), and locate Bouvet Island. You will find it where the Atlantic Ocean and the Southern Ocean meet (a magnifying glass may be required). Draw a circle around it (permission from the owner of the globe should be sought). Within a radius of 1000 kilometer, you will not find not another speck of land. There isn’t even a shipping lane. The nearest significant land area is Antarctica, 1700 kilometer away. The closest human settlement is Trista da Cunha, which is over 2000 kilometer distant, and is itself not particularly well connected. Cape Town and South Georgia are both 2500 kilometer away. In comparison, the International Space Station seems suburban. Go to Bouvet Island, and you will be the loneliest person on Earth. Only the 24 astronauts who have gone to the moon will have been further away from the rest of the world than you.

Getting there might be a bit of a journey, and visits tend to be few and brief. It is not only isolated, the surrounding ocean is as inhospitable as it comes. Think roaring forties – but in the fifties, and much colder. The average temperature in summer (January) is +1C, and the dominant weather is cloudy to foggy with storm. Precipitation is about 1 meter per year, largely as snow.

Bouvet is difficult to land on even in good weather, on account of the strong surf, which can quickly swamp a boat. It can be even harder to get off the island! There may be 2 to 4 storms each week, with little calm weather in between, and from March to October the island may be entirely inaccessible due to the relentless weather.

Through an accident of history, related to whaling, Bouvet Island is now a Norwegian possession. You wouldn’t have guessed, although the climate does provide a hint. It is a UNESCO world heritage site, an honour it shares with Mount Etna, the Hawaiian and the Kamchatka’s volcanoes. But you will be hard-pressed to find the visitor centre. Norway likes to put its protected environments where no one will be inconvenienced. (15% of its national parks are on Svalbard!)

Bouvet Island (called Bouvetøya in norwegian) is 49 square kilometer in area. About a quarter of this is taken up by a caldera, called Wilhelmplataet. The highest point of the island is on the caldera rim, Olavtoppen, at 780 meter; it was climbed for the first time only in 2012. The ice-filled caldera itself is 250 meter below the rim.

Expedition to the summit

The ice cover of the island is impressive: the black volcanic rock peaks out only at the coast. The rocky beaches especially on the west side are ice-free, but in most places the glaciers get rather close to the edge of the island. In the east, the ice cliffs tower 50 meters above the beach. About a third of the coast line has glaciers flowing into the sea; elsewhere, the rock cliffs are too steep to support a glacier, and the glacier ends above the cliff. The glaciers appear to be quite thin. How deep the ice is inside the caldera is not known: the summit is in almost perpetual cloud and very few people have been on the caldera.

Nyrøysa. The research station visible in the photo was washed into the sea in 2006. The shelf formed from a landslide, probably coming from the top right. Photo: Dolph Kessler

A low-lying shelf exists on the west coast, called Nyrøysa, which appeared sometime between 1955 and 1958. It is 2 kilometer wide, 500 meter deep and up to 50 meters high. For a while it was thought it had formed from a volcanic eruption, but later it was shown it must have come from a land slide. Elsewhere, much of the coast line is a steep cliff. The new shelf made landings much easier, and it was used to build shelters and automated weather stations. But they tended not to last, and often had disappeared by the time of the next landings. The cause is the catabatic winds coming down from the ice dome which can reach speeds up to 200 km/h.

There is one tiny satellite island to the southwest, Larsøya, which is ice-free.

If you like vegetation, there are some mosses and liverworts, and you can find a few lichens. Some of this has grown on the shelf, but most is on an ice-free region on the south coast, a few hundred meters up. Animal life is more abundant, in the form of seabirds, penguins, seals and elephant seals, principally on the western coastline. Many of the seals congregate on the Nyrøysa shelf on the west coast. There is also a large penguin colony there, of three different species, and one of the studies comments on the large loss of nests due to ‘interaction with seals’. I guess the egg shells have difficulty carrying the weight of several tons of elephant seal.

Astronaut Chuck Brady on Bouvet Island, with company

Bouvet Island has legendary status among ham radio enthusiasts. One of the ultimate achievements is to record worldwide contacts from this extreme location. The first to achieve this aim was Gus Browning in 1962, and the best-known ham operator here was Chuck Brady, who worked at a research station from December to early March in 2000/2001. Chuck (N4BQW) used a Mike Traffie HX-5B HEX-BEAM to make near 17,000 contacts. His team left the island only just in time: the recovery mission almost failed due to the autumn storms, and they left with only half an hour to spare. Chuck had previously flown as a NASA astronaut on the space shuttle. I wonder how the two experiences compared!

Volcanic activity

All deep-ocean islands are volcanic in nature. And because islands erode pretty fast, they tend to be younger volcanoes which are still active or slightly dormant. Bouvet is a shield volcano in the final stage of its life above water. The caldera shows that there have been significant eruptions in the past! Evidence that there is still life in the mountain comes from the presence of fumaroles, mainly on the north and west side, around the beaches. Reports suggest that they are short-lived. One fumarole was on a beach that eroded away, and has gone, and others show decline while new ones appear. It is possible that the fumaroles are activated by landslides: over decades the newly-exposed rock cools and the fumaroles disappear. In the Landsat image at the top of this post, there is a central peak in the caldera which shows there was an eruption after the caldera had formed. But it is not possible to see any details as it too is completely covered in snow.

The cliffs on the coast of Bouvet Island contain two main layers. The top layer contains a series of lava flows, with a few volcanoclastic deposits thrown in. The flows are largely basaltic, and have come from the caldera area. Only the youngest ones (Kapp Valdivia, Larsoya ) are rhyolitic and have formed domes on the flanks of the volcano. (A lava flow at Cape Meteor on the eastern flank has been argued to be 2000 or 4000 years old, but I have not found the source of this date.) The lower layer is made up from breccia and tuff, which formed in older, pyroclastic events. They may even have formed under water, as hyaloclastite.

The lower layer is quite soft and because it is at sea level, it makes the island rather susceptible to wave action. The wave erosion undercuts the cliffs; the result is landslides, which form beaches of debris. The beaches are quickly removed by the waves and the process begins again. In this way Larsoya became a separate island: erosion removed its link to the main island. The Nyrøysa shelf is eroding at a rate of between and 1 and 4 meters per year. How bad the erosion has become can be seen from the location of the caldera. It should be at the centre of the island, but instead it is on the western edge. The offset caldera makes the island look lopsided. It is caused by many centuries of wave erosion. The incessant westerlies have eaten away the exposed side of the island, and the erosion has now reached the caldera rim. That already tells you that Bouvet is in decline. The eruptions can’t keep up with the erosion and the island is getting smaller. Bouvet is past its prime and heading for retirement.

The landslides bring the basaltic rocks down to sea level, and the wave erosion turns it into a rough sand of basalt. In any other place, these blackest of black beaches would be famous. But here, in utter isolation, only the seals leave their impressions.

Changes at Larsoya between 1966 and 1979, caused by erosion. From https://brage.bibsys.no/xmlui/bitstream/handle/11250/173650/Skrifter175.pdf

Exploration

Jean-Baptiste Bouvet de Lozier, happy discoverer of the loneliest place on Earth

How did a Norwegian volcano (rare enough to begin with) end up with a French name? It came from Captain Jean-Baptiste Bouvet de Lozier, who discovered the speck in 1739. He saw it from a distance and did not sail around it: he reported it as the discovery of the southern continent. Due to its isolation and a map of rather questionable accuracy, it was not found again until 1808. James Lindsay re-discovered it, hundreds of kilometers from the position given by Bouvet, and named it Lindsay Island. One captain George Norris re-re-discovered it in 1825 and it acquired yet another name, Liverpool Island. He also reported a second island, 70 kilometer away, which he called Thompson island; it was never seen again and most likely never existed.

Because of this confusion, UK claims were deemed invalid, as it wasn’t clear which of these four islands they claimed, and the Norwegians ran away with the ownership.

Bouvet Island now has a registered internet domain, .bv. However, this domain has no known web sites.

Geology

The Mid-Atlantic Ridge (MAR), where the oceanic crust of the Atlantic Ocean is formed, runs from Iceland southward, ending at the Southern Ocean. Here it meets a complex fault which runs approximately east-west, connecting the southwestern part of the Indian Ocean Ridge to the South Sandwich Islands where a subduction zone is pulling in Patagonia. The end-point of the MAR is called the Bouvet Triple Junction – not entirely correct as Bouvet island is 250 kilometer away but there was nothing else here which could provide a name! The fault is called the Conrad Transform towards the west, and the Bouvet transform to the east, and separates the stable Antarctic plate, the African plate and the South American plate. Bouvet Island lies just south of the Bouvet Transform fault.

(Norway is in the curious position of owning both the southernmost (Bouvet) and northernmost (Jan Mayen) island of the MAR – and nothing else. And both are named after non-Norwegians.)

Between Bouvet Island and the MAR is the mysterious Spiess ridge. This is a massive volcanic feature, 80 kilometer long, with reaches to 320 meter below sea and has a large caldera. It seems young, perhaps 1 million year, although this is not well known.

Just looking at the sketch below shows how broken up the area is. Originally this was a more conventional-looking triple point, located some distance south of where the MAR ends now. The triple point moved up north, and every time it moved north the Conrad and Bouvet faults re-formed further north. The Spiess ridge appears to be one of the MAR sections that broke off, but another suggestion is that it was the formation of this ridge which caused the triple point to migrate northward.

‘Triple point’ is a funny expression, as in fact it is one point, not three. It is a place where three faults meet, so perhaps should be called ‘triple fault’, but as this would be confusing, sometimes it is called a ‘triple junction’. Each of the three faults can be of three varieties: a ridge (R), a trench (T), or a transform fault (F). A ridge forms if there is extension, i.e. seafloor spreading: you get a deep valley (a graben) and associated volcanism. A trench forms if there is subduction. A transform means that both sides slip past each other. Within a continental plate such a fault is called a strike-slip, but if it is between two different plates it is called a transform fault. Pure transform motion, sideways, is actually quite rare. An example of one is the South Iceland Seismic Zone. More commonly, a fault shows a bit of both extension and slip, as is the case on the Reykjanes Ridge. This case happens, for instance, where a strike-slip fault has a bend: you get areas of extension and areas of slip. This is called ‘transtensional’.

A triple junction is classified by which type of faults meet, for instance R-T-F if there is one spreading ridge, one subduction trench, and one transform fault (a somewhat unlikely configuration). An example of an R-R-R triple junction is at Afar, connecting the Red Sea, the Gulf of Aden and the African Rift. The end of the San Andreas fault, the Mendocino Triple Junction, is F-F-T. An F-F-F junction is physically not possible.

The Bouvet triple junction started out as an R-F-F junction, 20 million years ago. Currently the Conrad and Bouvet transforms are at an angle with respect to each other, but that is because the South American plate has rotated since. Originally, the two faults were parallel and would just have been the extension of each other. Later, the triple junction started to move north, the Conrad/Bouvet fault broke into pieces, and became R-R-R as spreading ridges.

At Bouvet Island, the spreading rate is currently 1.5 cm/yr. A deep valley has formed, but the southern wall of this valley is a kilometer higher than is should be, for unclear reason. This is where Bouvet Island is found.

Why did the ridge here, and only here, become volcanic? Noone knows. There is speculation about a ‘Bouvet Island hot spot’ but there is not much evidence for it. A thermal anomaly has been proposed, but this is just another word for a hot spot (albeit without the connotation of a plume). The lack of land over such a large surrounding area already shows that the region is not particularly volcanic. There are no island chains or even submarine chains.

Age

When did Bouvet Island form? Based on the distance from the newly formed spreading ridge, and the known spreading rate, the crust is dated to 4.5-5 million years. The volcano cannot be any older than that! The bedrock of the volcano is dated to 1.4 million years, and well-dated rocks around the 1950’s landslide are around 0.5 million years, so by that time the volcano existed. All measured rocks have normal magnetic orientation, meaning that they are younger than 1 million years: before that time, the magnetic field was reversed for a long period, but this is not seen in the Bouvet rocks. They all formed after the last field reversal.

The rate on erosion can give a rough age of the island. The 1950’s landslide formed a shelf 2 kilometer wide, 500 meter deep and on average 10 meter tall. This gives a total volume of 0.01 km3. The west side of the island has been eroded back by perhaps 5 kilometer. Assuming an average height of 400 meter, and a width of 5 kilometer, the eroded volume is 10 km3. If we assume that such a collapse happens once a century, the erosion has taken 100,000 years. At this rate, the island would erode by 5 cm per year which seems a bit high so perhaps such large collapses are not quite as frequent. At 1 cm per year, the age becomes half a million years. This is probably within the right ballpark. This poor island has never seen warm weather: when it popped up from beneath the sea, the ice ages were already in progress.

In another half a million years, Bouvet Island will have gone. Enjoy it while you can.

The mystery of the deserted life boat

Bouvet Island is home to its very own Marie Celeste mystery. In 1964, a team helicoptered in from HMS Protector found an abandoned lifeboat, half submerged in a lagoon on the newly-formed shelf. The leader, Alan Crawford, wrote What drama, we wondered, was attached to this strange discovery. There were no markings to identify its origin or nationality. On the rocks a hundred yards away was a forty-four gallon drum and a pair of oars, with pieces of wood and a copper flotation or buoyancy tank opened out flat for some purpose. Thinking castaways might have landed, we made a brief search but found no human remains. Clearly people had come ashore with very limited supplies, but there was no indication from where they had come, why, and how (if?) they had left.

The boat must have arrived after 1955 as the shelf did not exist before that. It could not have made a sea journey of any length. Whoever used the boat to get to Bouvet Island, left no other trace, but did have enough man power to drag a heavy boat 30 meters over rough stones away from the sea. Did a ship flounder and the poor survivors ended up here? Where they eaten by the elephant seals? (Unlikely.) Rescued in secret?

The mystery was described brilliantly by Mike Dash in a blog article of 2011. He did a trail through all reported ship losses showed nothing. The answer was slowly pieced together by the various commenters on the blog, in a piece of exemplary citizen detective work, and the following is based on their work. There are two parts to the answer. The second part was by radio, and the first involved birds.

Let’s begin with the second part of the answer. In 1962, the ham enthusiast Gus Browning came to Bouvet Island to pioneer radio transmissions from there. A far-flung (expensive) ham radio trip is called a DXpedition. Browning (W4BPD) visited Bouvet on his second DXpedition, from 26 to 28 November 1962. According to his own description, he landed at Cape Circoncision, at a flat area about the size of two football pitches. This must have been Nyrøysa, the only flat bit in the area, and not badly placed for his purpose. Radio signals to Asia are blocked from there by the island, but America and Europe would have been reachable. Browning brought a large petrol drum – forty-four gallon is about the right size. The copper box, opened out and flattened, would have been very useful to ground his antenna, although it seems a bit strange to bring damaged ware with you on such an expedition. Browning had hitched a lift on an icebreaker, and was taken to the island by life boat. The boat returned three days later to pick him up. However, that boat certainly had not floundered there: he made it back safely and never mentioned such a disaster. So it certainly wasn’t his boat that was found.

The first part to the story, involving the boat, began in November 1958, when a Soviet vessel visited Bouvet Island on an ornithological expedition. A report was published in the Information Bulletin of the Soviet Antarctic Expedition, volume 13 (1959), pages 97-99, by Gennady Solyanik, with the exciting title “Some Bird Observations on Bouvet Island”. The vessel, the Slava-9, was part of the Soviet whaling fleet, but their scientific work was done in the context of the International Geophysical Year. Slava-9 would have had two rowing boats, each able to carry 24 men.

A party of 10 men, scientists and sailors, including Solyanik came ashore close to Cape Circoncision. Again, this almost certainly was on the newly formed Nyrøysa, which had just formed and was by far the best landing place. Shortly after their arrival a hurricane began making it impossible for them to return. The boat would not have been up to that weather. They stayed there for three days, time used for more bird observations than they had planned! When the storm finally subsided, the man were evacuated with the Mi-1MG helicopter carried on the Slava-9. The helicopter pilot was Averyan Rzhevskiy, who later wrote about this event. The boat was left behind and found its final resting place here. The lagoon may not have been there yet: the rock fall would have compacted over time, and storm filled in the depression -and the boat- with water.

Gus Browning must have come ashore at the same place as the Soviet researchers, and found the camp left by the previous expedition. After four years, the boat would already have been in poor condition. The copper box was used as a flotation device on the boat. Browning found it, and put it to good use, and added his own debris to the camp site. But he didn’t report any of this – to him only the radio counted. In this way he left a double mystery, and became a beachcomber, the scavenger of the Marie Celeste of Bouvet Island.

Aliens

In 2004, the movie Alien vs. Predator hit the cinemas. It is set on the not-so-mythical island of Bouvetøya. Wikipedia writes: This film follows a group of archaeologists assembled by billionaire Charles Bishop Weyland (Henriksen) for an expedition near the Antarctic to investigate a mysterious heat signal. Sadly, the budding volcanologists go for the wrong heat signal, instead of interesting eruptions they uncover a pyramid, and mayhem begins.

This film is well worth missing, and although set on Bouvet island, it wasn’t actually filmed there, so it is of no volcanological interest either.

The end of the world

Bouvet Island would be a good place to site the Restaurant at the End of the World. It meets all requirements, including a total lack of other customers. The main menu will be penguin omelet with an algae side dish, and the fumaroles provide just enough heat for the hot plate. Better stay indoors – because of the ice and the clouds, there is not much to see, making it ideal for people who have seen it all. And from experience I can confirm that a penguin colony smells atrocious.

But underneath the ice lies a hidden world of which we know little. The caldera and the pyroclastics provides evidence for a violent past, but we don’t know when. And how did this volcano form? If it is related to the migrating triple junction, why is it not at the triple junction? Why is there no other volcanic island within 1000 kilometer? And why is it dying? The abandoned boat may have been the easiest of Bouvet’s mysteries. There is more here than meets the eye. Aliens, anyone?

One of the inhabitants of Bouvet island is the Southern Rockhopper Penguin. Also known as the Trømp.

Riddles

Last week Ardnamurchan was finally solved. Also Basil Faulty’s Guinea Pig was found. This week there are five brand new Riddles to chomp down on.

This week also features an image riddle. Good hunting!

Name

Last week’s points

Total

Bjarki

1

3

Daisaster

0

3

Albert

1

2

Spike Page

2

2

Thomas A

0

2

Bobbi

1

1

Chris Cookie Cooke

1

1

KarenZ

0

1

Collapsed fever of wild lava (iced near the singer and the ash in the area of Odadhahraun) – Kollotadyngja, answered by Irpsit (who also got a bonus point for listing every single volcanic feature in that region of Iceland)

First woman of Stevenson and Gary Cooper – Upola, answered by Virtual

Mined boring field of local spa (camel serai on the Ivory Road) – Tarso Voon, answered by Irpsit

Saint Peter of the Grog – Pelée in Martinique, answered by Inannamoon.

Reaching for #1 again “Collapsed fever of wild lava (iced near the singer and the ash)

Kverkfjoll? It is a caldera volcano..thus “collapsed” (although “fjoll” and “fall” might also be said to sound similar to non-Icelanders)….and it is Iced (Iceland, subglacial..duh)..and it is next to the ash (Askja) and the singer (Bardarbunga…. the bard..the singer).

This was the same reasoning I had for Herðubreið.
A shield tuya (iced, because it makes a cake flat when it is iced)
Collapsed sides,
Fever – mostly lava
wild – isolated and resided by outcasts and outlaws
Singer – BARDabunga
Ash – Askja

Krafla? It is a caldera, isolated, and fever or hiti in Icelandic, which is also the name of the High Temperature Instruments for Supercritical Geothermal Heat Extraction “HITI”. You know, Where they found they had a hole full of magma on the flanks of Krafla in 2011.

Collapsed fever of wild lava (iced near the singer and the ash)
Ash is Askja in Iceland. And singer is SöngsHofsdalur , a valley northeast of Askja.
These are the features that I found that could be a collapsed (fever) of lava:

flotudyngjuhraun (ravine lava), Flatadyngja (flat shield), Fjarholadydyngja (dyngja also seems to mean fever) but I know fever to be hiti, which is a common Icelandic name for craters, .

The other possibility is that hiti is simply viti, the hell explosion crater at Askja lake, there is a collapsed feature, the famous caldera itself, fever could also be Dyngja (Dyngjufjall is just next) but I dont seem to find a ‘”wild”,Villtu, feature.

If Bard is the singer and then it´s ash, the Askja, then #1 must be near Holuhraun. A collapsed fever, is a dyngja and hita, or a caldera, or a sunken rift, of wild lava, Dyngjuháls, Trolladyngja, Kistufell, are the dominant features there. There are many sunken features in that areas, and it´s indeed a wild vast lava field. Odadahraun.

I know the area, the borehole near Vitis/Vitismor, in Krafla caldera. But the local spa is urther southwest. Brunarborgarhraun, the lava fields that came down to the SW also include the vents of Leirhnjúkur, Hrossadalur, and Bjarnarflag. These lavas cover both the location of the Deep Drilling Project and the local spa Jardbodin.

It is a caldera, isolated, and fever or hiti in Icelandic, which is also the name of the High Temperature Instruments for Supercritical Geothermal Heat Extraction “HITI”. You know, Where they found they had a hole full of magma on the flanks of Krafla in 2011.

#3 – Damavand? Serai (caravan or medieval oasis city – Tehran was such for the Silk Road camel caravans) Also, Sari is a city to the north. Also, coal mining is in the area as well as some natural gas (boring field.)

Currently Irpsit is so close… (I am pondering a bonus point at this juncture since he listed almost all volcanic features in the correct area)
Odadhahraun is the location, but what is the crappy feature?

No other feature in the area is ipermanently ced other than the kojulls already mentioned. Askja,, Herdubreid, Krafla have some snow into summer too.
A range also called Dyngjufjoll Ytri might also be iced in summer. But the name seems not so special.

There are other lava fields in the area especially wesr of Askja such as Frambruni and Utbruni, but their names do not seem to give me any clue in that direction.

Other features include the deep valleys of Kidagil west of Askja, where a river fllows intot he waterrall Aldeyerfoss, and a canyon next to Askja east, called Drekagil, a dragon-like name translation I think.

Dyngjuvatn and Gaesavotn (goose lake) are the lakes in the area, but I always think #1 is probably a shield volcano or a lava field.

Finally, there are several large shield volcanoes other than Trolladyngja further north: Kollotadyngja, Ketildyngja,, and the mountains of Hruthálsar and Herdubreidarfjoll. I will look into these translations.

Sveinagja is another possibility: this is the large lava field fissure created in 1874 prior to the caldera of Askja. Oh man, this fits into all clues, its a collapsed (caldera() lava field, in the wild and vast area of Odadahraun.

Odadahraun goes between Bardarbunga almost all the way to Krafla.

North of Krafla is Theistjarreyjarbunga but that´s too far north I think.

The dynamic fluids are already moving, it seems in Landamannalaugar, Torfajokull. I wrote 4 feature with K: Kollotadyngja (a shield north of Askja), Ketildyngja (also shield north of Askja), Krafla (caldera), and Kidagil (a canyon).

I’m intrigued by that one too. I’ve been watching for a couple of years and I don’t *think* I’ve seen a swarm that big in that particular location. My memory could well be deceiving me. Not that it looks like an eruption or anything – way too small – but I wonder what it’s up to.

In regards of the earthquakes in the eastern half of the Torfajökull Caldera we now have a plot showing that this looks like an earthquake stack that often are associated with magma conduits leading up from a deep magma reservoir, or from the MOHO.
This is a bit surprising since the area is mostly known for shrinkage earthquakes caused by old cooling magma. As such it is the first time that we may have evidence of reactivation of the old magma system.

One has to put this into larger perspective of what is happening in Iceland in recent years.

Every 140 years or so, we see an increase in hotspot activity and also in volcanic eruptions all across Iceland. So we should expect several eruptions in unexpected volcanoes across Iceland, and also many more intrusions (failed eruptions) in even more volcanoes.

In the previous cycle, several of these less expected volcanoes erupted: Reykjanes (out in the sea), some spots in the vicinity of Hekla, Kverfjoll, Esjufjoll, Askja (with a big one), Thordarhyrna . In other former cycles, Langjokull and Eyjafjallajokull also erupted. In many cycles, Grimsvotn and Bardarbunga increase their eruptive frequency many-fold.

So I am expecting many of the active volcanoes in Iceland to experience some sort of this phenomena, magmatic intrusions, some of which will lead to eruptions.

We already had intrusions in Oraefajokull, Tungnafellsjokull, Krisuvik, continuous ones at Herdubreid. And now Torfajokull. But there are many other volcanoes that might experience some unrest in the future, like Hofsjokull, Langjokull, Kverfjoll naturally being so near Bardarbunga, Theistareykarbunga, etc….

Yeah, anything much deeper than 2.5 km is starting to get past the supercritical point of water. {22.1 MPa} I don’t remember the exact depth, but below that, water exists as both a gas and a liquid due to the pressure. Fluid percolating above that pressure depth will flash to steam, but below it, it can’t. You can see this effect in a quake vs depth plot at Yellowstone quite easily. It’s also why the super deep oceanic volcanic systems don’t release steam until they get closer to the surface. Bob, south of La Restinga in El Hierro churned and boiled because it was a pretty shallow vent.

Note: We called it “Bob” because it deserved better than to be named after some obscure fish story. It was also easier to pronounce than “Eyjafjallajökull” and we figured that the vapid news idiots could use a break.

Also, remember that we are not the official naming authority. The name the thing actually carries depends on the organizations of the country it is in. So the vague fish name is probably the official one.

‘Hyljafiskaheitieldfjall’ ? 😛 {Not gonna be anywhere near accurate. It’s not a mountain since it never actually got above the surface. So the fjall bit is way off. And other than the floaters, it never really produced much in the way of magma, at least that can be easily seen. Maybe some Hyaloclastite and pillow lavas, but you would have to dive to get samples from the seafloor… unless you buy a collected floater from someone local. In that case, you would get a lump of porus rock that looks like chocolate swirls (basalt) inside of vanilla icecream (silica rich stuff derived from the layer of phyllite under the island. Laid down when the Atlantic was still just a Jurassic era basin.)

Phyllite is midway between slate and schist. The pressures at that level are only high enough to make phyllite. Schist doesn’t occur untile you get much greater pressures, such as when the area gets shoved under a mountain range during an orogenic phase.

Many others clearly are and that’s all good but I find them just an annoyance. May I make a gentle suggestion? Have TWO articles running – one for volcanology and only volcanology; one for riddles and answers and only riddles and answers. That way I (and others) wouldn’t have to wade through a couple of hundred riddle attempts to find the volcanology nuggets and news I’m looking for! 🙂

The long term plan is to have them in a separate area as I mentioned in my latest article (a ‘sheepy bar’ of sorts) where Friday riddles are put and the discussion can tangent in what ever direction it likes (as long as it stays nice). It’s on my wish-list to do, but I’ve been too bogged down in life events and work to set something up yet. Friday riddles will be in the main article today, but at some point, they will move to a separate area.

As with all things in life it is all a juggling act.
Lately the comments had dwindled quite a bit in here. So, we tried to reinstate the riddles to get back a bit of the community feeling. And that worked handsomely.
The riddles are very popular.
That being said, the format of the riddling and where the answers will be made is changeable, and will be changed as and when we do get around to making the necessary technical changes we need to do. But, as you know we do have a lot of things to do, and not all the time in the world.
So, at least for a little while they will remain where they are, until our over-worked technical wizards get around to producing “The Sheepy Dalek 2.0”.

The riddles have dominated the comment section in recent weeks. Obviously post authors would appreciate discussion on their posts! Riddles are great, but ideally you get more of a mix of riddling and discussing. I think the powers-that-be are considering blog developments. Let’s see what the next post brings.

Hi, one thought I have for 2.0 and the riddles, I recall we did house them for a time in one location. From memory, each week the new riddles were added to the same page and it made it difficult to scroll through the answers and decipher which ones were which. If you do house them in location would it be possible to have a new page/post for each week? Thanks 🙂

But the activity is staying below 5 km. Actually, I think its my wife doing something! The first swarm came when she was about flying to Iceland. Now, this is coming when she is about to go home. I will check with her when she is back home!